第143页 - 通城学典课时作业本九年级英语译林版南通专版

Four minutes.

He believes in the future, millions of people will live and work in space.

By moving polluting businesses away from the Earth and into space.

Because rockets create huge amounts of pollution(as they burn tons of fuel in order to fly into sky.

I think it can help us protect the planet.(言之有理即可)

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